fix: Fall back to the serialized body when UDF source misses globals by Daksha1611 · Pull Request #6816 · feast-dev/feast

Daksha1611 · 2026-09-06T17:27:13Z

What this PR does / why we need it:

Source-first UDF rehydration execs only the UDF's own source into a namespace seeded
with pandas/numpy. A UDF that reads a helper, constant, or aliased import from its
defining module cannot resolve those names — but the exec still succeeds, because a
function body's free variables are only looked up when the function is called.

resolve_udf therefore treated rehydration as successful and never fell back to the
dill body, even when that body carried the captured globals and would have run. The
failure surfaced later as a NameError during retrieval, so an on-demand feature view
that served correctly before started raising once it was loaded from the registry:

NameError: name 'scaled' is not defined

This validates the rebuilt callable before accepting it: walk its LOAD_GLOBAL
operands, plus those of nested code objects (inner functions, comprehensions), and
return None when a name resolves in neither the exec namespace nor builtins.
resolve_udf then falls back to the serialized body exactly as it did before.

Only LOAD_GLOBAL operands are inspected. co_names also contains attribute names
(df.columns), so checking that instead would flag working UDFs and push them onto the
dill path for no reason — there's a regression test covering that.

Self-contained UDFs are unaffected and still take the source path, so the Spark
segfault and cross-Python-version benefits of source-first rehydration are kept intact.

Which issue(s) this PR fixes:

Fixes #6815

Checks

I've made sure the tests are passing.
My commits are signed off (git commit -s)
My PR title follows conventional commits format

Testing Strategy

Unit tests
Integration tests
Manual tests
Testing is not required for this change

Four regression tests added to sdk/python/tests/unit/transformation/test_udf_rehydrate.py.
Three of them fail on master and pass here; the fourth (test_attribute_access_is_not_ mistaken_for_a_missing_global) passes both ways by design, guarding the co_names
false-positive trap described above.

Verified end to end as well: an ODFV applied from a script, then read back in a separate
process holding only the registry, returned NameError before this change and the
correct value after.

sdk/python/tests/unit filtered to the transformation / on-demand / feature-view areas:
314 passed, 5 skipped. The 9 errors in that run are MongoDB testcontainers failing to
start locally and are present on master too.

ruff check, ruff format --check and mypy are clean on both changed files.

Misc

The pre-existing test_resolve_udf_prefers_source_over_garbage_dill_body still passes,
which confirms self-contained UDFs continue to prefer source over the body.

Source-first rehydration execs only the UDF's own source into a namespace seeded with pandas/numpy. A UDF that reads a helper, constant, or aliased import from its defining module has no way to resolve those names, but the exec still succeeds, because a function body's free variables are only looked up when it is called. resolve_udf therefore treated rehydration as successful and never fell back to the dill body, even when that body carried the captured globals and would have run. The failure surfaced later as a NameError during retrieval, so an on-demand feature view that served correctly before started raising once it was loaded from the registry. Validate the rebuilt callable before accepting it: walk its LOAD_GLOBAL operands, and the operands of nested code objects, and return None when a name resolves in neither the exec namespace nor builtins. resolve_udf then falls back as it did before. Only LOAD_GLOBAL is inspected. co_names also holds attribute names, so checking it would flag working UDFs and push them onto the dill path for no reason. Self-contained UDFs are unaffected and still take the source path, keeping the Spark and cross-Python-version benefits intact. Signed-off-by: Daksha1611 <[email protected]>

codecov-commenter · 2026-09-09T11:08:12Z

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✅ All modified and coverable lines are covered by tests.
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@@            Coverage Diff             @@
##           master    #6816      +/-   ##
==========================================
- Coverage   47.08%   47.08%   -0.01%     
==========================================
  Files         419      419              
  Lines       51878    51875       -3     
  Branches     7525     7525              
==========================================
- Hits        24429    24427       -2     
+ Misses      25700    25699       -1     
  Partials     1749     1749

Flag	Coverage Δ		*Carryforward flag
go-feature-server	`30.58% <ø> (ø)`
python-unit	`48.39% <ø> (-0.01%)`	⬇️	Carriedforward from 5ad5592

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Files with missing lines	Coverage Δ
sdk/python/feast/transformation/udf_rehydrate.py	`64.60% <ø> (-0.06%)`	⬇️

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Daksha1611 · 2026-10-06T07:56:37Z

Gentle ping for a review when someone has time. #6818 and #6820 are small, independent fixes in the same area.

shuchu

lgtm

# [0.68.0](v0.67.0...v0.68.0) (2026-11-10) ### Bug Fixes * add watch verb on clusterroles and clusterrolebindings for feast-operator ([#7062](#7062)) ([b6bdda4](b6bdda4)) * Apply on demand feature views in SparkRetrievalJob.to_spark_df() ([#6993](#6993)) ([f416309](f416309)) * Break event timestamp ties by created timestamp in Milvus write batches ([#7084](#7084)) ([bbaca76](bbaca76)) * Break event timestamp ties by created timestamp in the Dask offline store ([#6952](#6952)) ([eb93b08](eb93b08)) * Build the Go feature server image in two stages ([1e5e90c](1e5e90c)), closes [#7060](#7060) * Fall back to the serialized body when UDF source misses globals ([#6816](#6816)) ([f61079f](f61079f)) * Install patched libbrotli1 to address DSA-6582-1 ([#7096](#7096)) ([d458393](d458393)) * Keep description, tags and nested types of ODFV schema fields ([8ef6e75](8ef6e75)) * Keep entity columns out of StreamFeatureView proto features ([#7033](#7033)) ([d520584](d520584)) * Keep the metrics server running when a Gunicorn worker exits ([#7012](#7012)) ([68c5d54](68c5d54)), closes [#7011](#7011) * Key registry proto caches on the proto, not its id() ([#7085](#7085)) ([147adad](147adad)) * Log ODFV materialization skips instead of printing them ([#7117](#7117)) ([8fdcee7](8fdcee7)) * Pin build dependencies of source builds to the CI lock ([#7104](#7104)) ([dec2f24](dec2f24)) * Populate spec.project in registry REST feature view responses (#… ([#7037](#7037)) ([e304a84](e304a84)) * Preserve colliding source timestamps in Dask retrieval ([#7071](#7071)) ([1396c88](1396c88)) * Preserve Dask historical requests without eligible features ([#7000](#7000)) ([fff09f7](fff09f7)) * Read None elements of UUID and Decimal lists as None ([#7039](#7039)) ([03f30fe](03f30fe)) * Retire the support of Python3.10 ([#7101](#7101)) ([a56766e](a56766e)), closes [#7104](#7104) [#7089](#7089) [#7106](#7106) [#7105](#7105) * Serialize UUID and TimeUuid entity keys ([#7032](#7032)) ([0c845a1](0c845a1)) * Stop the Ray engine from hiding materialization errors ([#7026](#7026)) ([7903e2e](7903e2e)), closes [#7024](#7024) * **ui:** stop treating the monitoring baseline as the latest window ([#7056](#7056)) ([0f01802](0f01802)), closes [#7054](#7054) * Use date-only bounds for partition filters built from string timestamps ([#7116](#7116)) ([b1f2168](b1f2168)) * Validate entity column types in feast dbt import ([#7067](#7067)) ([abca80c](abca80c)), closes [#5876](#5876) * Warm up the whole DynamoDB connection pool ([#6985](#6985)) ([8ce548c](8ce548c)) ### Features * Add --gc-freeze option to feast serve ([#7089](#7089)) ([aad0c15](aad0c15)) * Add native complex types and scalar index tags to the Milvus online store ([#7120](#7120)) ([f7068d6](f7068d6)) * Add num_partitions and partition_key_isolation to the Milvus online store ([#7083](#7083)) ([68de84e](68de84e)), closes [#6940](#6940) * Add Pinecone online store integration ([#6585](#6585)) ([7a84f2a](7a84f2a)) * Add PolarisSource and PolarisProvider for Apache Polaris ([#7006](#7006)) ([386759c](386759c)) * Add row deletion to the Milvus online store ([#7082](#7082)) ([d3e2041](d3e2041)) * Add upstream FeatureView lineage support for PushSource ([#6853](#6853)) ([c9b9d72](c9b9d72)) * Optional nameless pre-computed vectors with a schema fingerprint ([#7077](#7077)) ([9420fac](9420fac)) ### Performance Improvements * Scan Lance sources lazily in the DuckDB offline store ([1299e4e](1299e4e))

…east-dev#6816) Source-first rehydration execs only the UDF's own source into a namespace seeded with pandas/numpy. A UDF that reads a helper, constant, or aliased import from its defining module has no way to resolve those names, but the exec still succeeds, because a function body's free variables are only looked up when it is called. resolve_udf therefore treated rehydration as successful and never fell back to the dill body, even when that body carried the captured globals and would have run. The failure surfaced later as a NameError during retrieval, so an on-demand feature view that served correctly before started raising once it was loaded from the registry. Validate the rebuilt callable before accepting it: walk its LOAD_GLOBAL operands, and the operands of nested code objects, and return None when a name resolves in neither the exec namespace nor builtins. resolve_udf then falls back as it did before. Only LOAD_GLOBAL is inspected. co_names also holds attribute names, so checking it would flag working UDFs and push them onto the dill path for no reason. Self-contained UDFs are unaffected and still take the source path, keeping the Spark and cross-Python-version benefits intact. Signed-off-by: Daksha1611 <[email protected]> Co-authored-by: Shuchu Han <[email protected]> Signed-off-by: Shuchu Han <[email protected]>

# [0.68.0](feast-dev/feast@v0.67.0...v0.68.0) (2026-11-10) ### Bug Fixes * add watch verb on clusterroles and clusterrolebindings for feast-operator ([feast-dev#7062](feast-dev#7062)) ([b6bdda4](feast-dev@b6bdda4)) * Apply on demand feature views in SparkRetrievalJob.to_spark_df() ([feast-dev#6993](feast-dev#6993)) ([f416309](feast-dev@f416309)) * Break event timestamp ties by created timestamp in Milvus write batches ([feast-dev#7084](feast-dev#7084)) ([bbaca76](feast-dev@bbaca76)) * Break event timestamp ties by created timestamp in the Dask offline store ([feast-dev#6952](feast-dev#6952)) ([eb93b08](feast-dev@eb93b08)) * Build the Go feature server image in two stages ([1e5e90c](feast-dev@1e5e90c)), closes [feast-dev#7060](feast-dev#7060) * Fall back to the serialized body when UDF source misses globals ([feast-dev#6816](feast-dev#6816)) ([f61079f](feast-dev@f61079f)) * Install patched libbrotli1 to address DSA-6582-1 ([feast-dev#7096](feast-dev#7096)) ([d458393](feast-dev@d458393)) * Keep description, tags and nested types of ODFV schema fields ([8ef6e75](feast-dev@8ef6e75)) * Keep entity columns out of StreamFeatureView proto features ([feast-dev#7033](feast-dev#7033)) ([d520584](feast-dev@d520584)) * Keep the metrics server running when a Gunicorn worker exits ([feast-dev#7012](feast-dev#7012)) ([68c5d54](feast-dev@68c5d54)), closes [feast-dev#7011](feast-dev#7011) * Key registry proto caches on the proto, not its id() ([feast-dev#7085](feast-dev#7085)) ([147adad](feast-dev@147adad)) * Log ODFV materialization skips instead of printing them ([feast-dev#7117](feast-dev#7117)) ([8fdcee7](feast-dev@8fdcee7)) * Pin build dependencies of source builds to the CI lock ([feast-dev#7104](feast-dev#7104)) ([dec2f24](feast-dev@dec2f24)) * Populate spec.project in registry REST feature view responses (#… ([feast-dev#7037](feast-dev#7037)) ([e304a84](feast-dev@e304a84)) * Preserve colliding source timestamps in Dask retrieval ([feast-dev#7071](feast-dev#7071)) ([1396c88](feast-dev@1396c88)) * Preserve Dask historical requests without eligible features ([feast-dev#7000](feast-dev#7000)) ([fff09f7](feast-dev@fff09f7)) * Read None elements of UUID and Decimal lists as None ([feast-dev#7039](feast-dev#7039)) ([03f30fe](feast-dev@03f30fe)) * Retire the support of Python3.10 ([feast-dev#7101](feast-dev#7101)) ([a56766e](feast-dev@a56766e)), closes [feast-dev#7104](feast-dev#7104) [feast-dev#7089](feast-dev#7089) [feast-dev#7106](feast-dev#7106) [feast-dev#7105](feast-dev#7105) * Serialize UUID and TimeUuid entity keys ([feast-dev#7032](feast-dev#7032)) ([0c845a1](feast-dev@0c845a1)) * Stop the Ray engine from hiding materialization errors ([feast-dev#7026](feast-dev#7026)) ([7903e2e](feast-dev@7903e2e)), closes [feast-dev#7024](feast-dev#7024) * **ui:** stop treating the monitoring baseline as the latest window ([feast-dev#7056](feast-dev#7056)) ([0f01802](feast-dev@0f01802)), closes [feast-dev#7054](feast-dev#7054) * Use date-only bounds for partition filters built from string timestamps ([feast-dev#7116](feast-dev#7116)) ([b1f2168](feast-dev@b1f2168)) * Validate entity column types in feast dbt import ([feast-dev#7067](feast-dev#7067)) ([abca80c](feast-dev@abca80c)), closes [feast-dev#5876](feast-dev#5876) * Warm up the whole DynamoDB connection pool ([feast-dev#6985](feast-dev#6985)) ([8ce548c](feast-dev@8ce548c)) ### Features * Add --gc-freeze option to feast serve ([feast-dev#7089](feast-dev#7089)) ([aad0c15](feast-dev@aad0c15)) * Add native complex types and scalar index tags to the Milvus online store ([feast-dev#7120](feast-dev#7120)) ([f7068d6](feast-dev@f7068d6)) * Add num_partitions and partition_key_isolation to the Milvus online store ([feast-dev#7083](feast-dev#7083)) ([68de84e](feast-dev@68de84e)), closes [feast-dev#6940](feast-dev#6940) * Add Pinecone online store integration ([feast-dev#6585](feast-dev#6585)) ([7a84f2a](feast-dev@7a84f2a)) * Add PolarisSource and PolarisProvider for Apache Polaris ([feast-dev#7006](feast-dev#7006)) ([386759c](feast-dev@386759c)) * Add row deletion to the Milvus online store ([feast-dev#7082](feast-dev#7082)) ([d3e2041](feast-dev@d3e2041)) * Add upstream FeatureView lineage support for PushSource ([feast-dev#6853](feast-dev#6853)) ([c9b9d72](feast-dev@c9b9d72)) * Optional nameless pre-computed vectors with a schema fingerprint ([feast-dev#7077](feast-dev#7077)) ([9420fac](feast-dev@9420fac)) ### Performance Improvements * Scan Lance sources lazily in the DuckDB offline store ([1299e4e](feast-dev@1299e4e)) Signed-off-by: Shuchu Han <[email protected]>

Daksha1611 requested a review from a team as a code owner September 6, 2026 17:27

Daksha1611 added 3 commits September 11, 2026 12:28

Merge branch 'master' into fix/odfv-udf-globals-rehydrate

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Merge branch 'master' into fix/odfv-udf-globals-rehydrate

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Merge branch 'master' into fix/odfv-udf-globals-rehydrate

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Daksha1611 and others added 2 commits October 6, 2026 13:44

Merge branch 'master' into fix/odfv-udf-globals-rehydrate

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Merge branch 'master' into fix/odfv-udf-globals-rehydrate

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shuchu approved these changes Nov 10, 2026

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shuchu merged commit f61079f into feast-dev:master Nov 10, 2026
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patelchaitany mentioned this pull request Nov 10, 2026

chore: Sync upstream feast-dev/feast master opendatahub-io/feast#288

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chore: Sync upstream feast-dev/feast stable (0.68.0) opendatahub-io/feast#291

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Automated Sync from main to stable red-hat-data-services/feast#630

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fix: Fall back to the serialized body when UDF source misses globals - #6816

fix: Fall back to the serialized body when UDF source misses globals#6816
shuchu merged 6 commits into
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Daksha1611:fix/odfv-udf-globals-rehydrate

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Daksha1611 commented Sep 6, 2026

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